The present invention relates to a copy protection apparatus for preventing digital data recorded on a recording medium from an unauthorized copy from the recording medium. The present invention also relates to an information recording medium used in this copy protection apparatus.
Conventional multimedia information (e.g., image and audio data) recording media are developed in the form of a floppy disk, compact disk, DVD (Digital Video Disk), or the like.
Since digital data is recorded directly (compressed and coded data which can be decoded are also included) on the various types of digital recording media described above, the recorded data can be easily copied to other media without any loss, thus suffering problems such as copyright infringement.
To solve these problems, a method of encryption digital data and recording the encrypted digital data on a recording medium is available. However, deficiencies in management of encryption keys used in encrypting the recorded data inevitably allow data copy.